Selection of Processes\Subprocesses

Kindly give your comments on the following queries :
1.Say, in OPP if an organization has selected some process/subprocess (SP 1.1) for performance analysis. A critical criterion for selectionof process or subprocess is its historical stability. To ensure thisdoes the organization needs to use statistical techniques right fromthe beginning of the data collection for that process/subprocess?
2.In QPM, whether the projects have to select the subprocess fromprocess/subprocess identified in OPP or need to select based on their project specific objectives?

Let us first consider the OPP SP 1.1 question. How is it possible to know that a process, or sub-process for that matter, is stable without having already performed some sort of statistical analysis on the historical data? What I think the actual question you may be asking below is at what point does it make sense to begin using statistical techniques. Obviously, OPP SP 1.1 is where you want to be when you reach Maturity Level 4. However, it does take some time and thought before arriving here. So, as an organization begins its ML 4 journey implementing OPP SP 1.1, it may NOT have enough historical data to select the processes or sub-processes. Therefore, the organization must spend some time collecting and analyzing the data before it is smart enough to know if it has a stable process or sub-process or one that can be stabilized. As the organization's processes become more and more stable, the application of statistical techniques may prove insightful. The stabilization of process execution, as reflected in the resulting process data, provides the opportunity to apply more sophisticated analytical techniques, including statistical methods. So it is not necessary to "use statistical techniques right from the beginning of the data collection;" rather statistical techniques can be applied once the process is consistently executed as reflected by the resulting data stability. Therefore, the organization has to devote the effort to data analysis to determine if OPP SP 1.1 can be implemented.

QPM works in conjunction with OPP. The project’s quality and process performance objectives are derived from the organization’s quality and process performance objectives. And the processes and sub-processes being quantitatively and statistically managed by the project are selected from those specified in OPP. If not, what would be the value of OPP SP 1.1? OPP sets up the infrastructure to allow the projects to perform QPM. However, that being said, a project may find that it has unique characteristics or customer objectives that warrant the statistical management of one or more subprocesses for which no process performance baseline has yet been established. In such a case, the project would select that subprocess for statistical management in QPM SG2, establish spec limits for the expected process performance, and use that as its foundation for quantitative management. Once sufficient process data have been accumulated by the project, the actual Upper Control Limit (UCL) and Lower Control Limit (LCL) can be established and used (and process stability and process capability can be verified or denied). Note that this information should be fed back to OPP for potential use on future projects.